Prevalence of Salmonella spp. in broiler chicken flocks in northern Poland in 2014–2016

Zoonotic serotypes of Salmonella enterica subsp. enterica are an important biological factor that poses a threat to public health, and broilers are often asymptomatic carriers of these bacteria. The aim of this study was to analyze the prevalence of Salmonella spp. and Salmonella serotypes in broiler chicken flocks in northern Poland in 2014–2016. The study was conducted on commercial flocks monitored by the Institutes of Veterinary Hygiene in Gdańsk and Olsztyn in 2014–2016. A total of 4,331 samples were investigated. Identification of Salmonella spp. was performed by a culture-dependent method followed by biochemical and serological confirmation tests, in accordance with Polish Standards. The total percentage of infected flocks in northern Poland reached 1.57%. The prevalence of Salmonella spp. in broiler chickens decreased from 2.19% in 2014 to 1.22% in 2016. The percentage of flocks infected with S. Enteritidis and S. Typhimurium was 1.18% and 0.12%, respectively (S. Enteritidis and S. Typhimurium were detected in 1.29% of flocks). The most common serotypes that had not been covered by the control programme were S. Mbandaka (0.14%), S. Infantis (0.07%) and, sporadically, S. Kentucky and S. Anatum. The percentage of infected flocks was higher (by 0.26%) in the Pomeranian Region than in the Region of Warmia and Mazury, and it increased over the analyzed period – the highest number of positive samples were found in 2016 (2.04%). In the Region of Warmia and Mazury, the percentage of infected flocks was highest in 2014 (3.08%); in 2014–2016, the number of positive samples decreased steadily to reach 0.41% in 2016. In the analyzed regions, the incidence of human salmonellosis was correlated with the percentage of infected broiler flocks

BTLA-derived peptides as inhibitors of BTLA/HVEM complex formation – design, synthesis and biological evaluation

Immune checkpoints can be divided into co-stimulatory and co-inhibitory molecules that regulate the activation and effector functions of T cells. The co-inhibitory pathways mediated by ICPs are used by cancer cells to escape from immune surveillance, and therefore the blockade of these receptor/ligand interactions is one of the strategies used in the treatment of cancer. The two main pathways currently under investigation are CTLA-4/CD80/CD86 and PD-1/PD-L1, and the monoclonal Abs targeting them have shown potent immunomodulatory effects and activity in clinical environments. Another interesting target in cancer treatment is the BTLA/HVEM complex. Binding of BTLA protein on T cells to HVEM on cancer cells leads to inhibition of T cell proliferation and cytokine production. In the presented work, we focused on blocking the HVEM protein using BTLA-derived peptides. Based on the crystal structure of the BTLA/HVEM complex and MM/GBSA analysis performed here, we designed and synthesized peptides, specifically fragments of BTLA protein. We subsequently checked the inhibitory capacities of these compounds using ELISA and a cellular reporter platform. Two of these peptides, namely BTLA(35−43) and BTLA(33−64)C58Abu displayed the most promising properties, and we therefore performed further studies to evaluate their affinity to HVEM protein, their stability in plasma and their effect on viability of human PBMCs. In addition, the 3D structure for the peptide BTLA(33−64)C58Abu was determined using NMR. Obtained data confirmed that the BTLA-derived peptides could be the basis for future drugs and their immunomodulatory potential merits further examination

Amino acids, glycans, peptides and proteins in the diagnostic and therapeutic pathways of the 21st century civilization diseases : design, physicochemical and structural characterisation

The civilization diseases of the 21st century are non-infectious disorders, affecting a large part of modern society. They are associated with the significant development of industry and technology, and hence with environmental pollution and an unhealthy lifestyle. These factors have led to the development of many civilization diseases, which currently include: cardiovascular diseases, respiratory diseases, diabetes, obesity, malignant tumors, gastrointestinal diseases, mental disorders and allergic diseases. The development of technologies, including modern therapies and new drugs, resulted in increase in life expectancy. This creates a global problem of an aging population with an increasing number of diseases of the old age, i.e. dementias. In addition, sedentary lifestyles and changing diets are the reasons why more and more people develop metabolic diseases, as well as neurological and cognitive disorders characterized by progressive damage to nerve cells and dementia. Currently, problem on a global scale is also the growing resistance to existing antimicrobial drugs. Therefore, the scientists face many challenges related to searching for the causes of these diseases, their diagnosis and treatment. Scientific research conducted at the Department of Biomedical Chemistry at the Faculty of Chemistry of the University of Gdańsk is part of this research trend. In this publication, we discuss various research topics with the long-term aim of solving the problems associated with the diseases mentioned above. The following chapters are dedicated to (i) looking for new effective fluorophores with diagnostic and anti-cancer activity; (ii) designing of new compounds with antibacterial and antiviral activity and their synthesis; (iii) investigating the mechanisms of amyloid deposit formation by human cystatin C and possibilities of inhibition of this process; (iv) designing and studies of compounds activating the proteasome with the potential to suppress the development of neurodegenerative diseases; (v) designing peptide fibrils and hydrogels as drug carriers; (vi) searching for peptide inhibitors of immune checkpoint as potential drugs for immunotherapy; (vii) studying the mechanism of action of selected herpesviruses by determining the structure of viral proteins and (viii) studying the composition of natural glycans and glycoconjugates in order to better understand the mechanisms of interaction of bacteria with the environment or with the host